The present invention relates to a method for controlling a wall saw system during the creation of a separation cut.
A method is known from EP 1 893 173 B1 for controlling a wall saw system during the creation of a separation cut in a workpiece between a first end point and a second end point. The wall saw system comprises a guide rail and a wall saw with a saw head, a motor-driven feed unit that moves the saw head parallel to a feed direction along the guide rail, and at least one saw blade attached to a saw arm of the saw head and driven by a drive motor about an axis of rotation. The saw arm is pivotable by means of a pivoting motor about a pivot axis. By a pivoting movement of the saw arm about the pivot axis, the penetration depth is changed in the workpiece. The motor-driven feed unit comprises a guide carriage and a feed motor, wherein the saw head is mounted on the guide carriage and moved via the feeding motor along the guide rail. To monitor the wall saw system a sensor device is provided with a pivot angle sensor and a displacement sensor. The pivot angle sensor measures the present pivot angle of the saw arm and the displacement sensor measures the actual position of the saw head on the guide rail. The measured values for the current pivot angle of the saw arm and the actual position of the saw head are regularly sent to a control unit of the wall saw.
The known method for controlling a wall saw system is divided into a preparation part and processing of the separation cut. In the preparation part the operator sets at least the saw blade diameter of the saw blade, the positions of the first and second end point in the feed direction and the final depth of the separation cut; other parameters can be the material of the workpiece to be machined and the dimensions of embedded rebar. From the parameters entered, the control unit determines an appropriate main cutting sequence of main cuts for the separation cut, wherein the main cutting sequence comprises at least a first main cut having a first main cutting angle of the saw arm and a first diameter of the saw blade used, and a following second main cut with a second main cutting angle of the saw arm and a first diameter of the saw blade used.
After starting the controlled processing the saw head is positioned in a starting position. In the starting position the saw arm is pivoted in a negative direction of rotation about the pivot axis and arranged below the first main negative cutting angle. The saw head is moved in a positive feed direction along the guide rail in the direction of the second end point, wherein the saw arm during the processing is in a pulling arrangement. Before reaching the second end point the saw head is stopped and reset far enough in a negative feed direction contrary to the positive feed direction. The saw arm is pivoted in a positive direction of rotation opposite to the negative direction of rotation from the negative first main cutting angle in a positive main cutting angle of the saw arm.
In a first variant the saw arm is pivoted from the negative first main cutting angle to the positive first main cutting angle and the saw head is moved in the positive feed direction to the second end point, wherein the saw arm is in an abutting arrangement. Upon reaching the second end point the feed direction is reversed and the saw head is moved in the negative feed direction to the first end point, wherein the saw arm is in a pulling arrangement. Prior to the first end point the saw head is stopped and reset sufficiently far in the positive feed direction. The saw arm is pivoted from the positive first main cutting angle in the negative first main cutting angle and the saw head is moved in the negative feed direction to the first end point, wherein the saw arm is in an abutting arrangement.
In a second variant the saw arm is pivoted from the negative first main cutting angle to the positive second main cutting angle and the saw head is moved from the positive feed direction to the second end point, wherein the saw arm is in an abutting arrangement. Upon reaching the second end point the feed direction is reversed and the saw head is moved in the negative feed direction to the first end point, wherein the saw arm is in a pulling arrangement. Before the first end point the saw head is stopped and set far enough hack in the positive feed direction. The saw arm is pivoted from the negative second main cutting angle and the saw head is moved in the negative feed direction to the first end point, wherein the saw head is in an abutting arrangement. If the second main cut is the last main cut, the saw arm is pivoted in the positive second main cut angle. If a third main cut is performed with the third main cut angle, the saw arm is pivoted from the negative second main cutting angle to the positive third main cutting angle of the third main cut. The method steps are repeated until the final depth of the separation cut is reached.
The known method for controlling a wall saw system has the disadvantage that the saw head before the processing is reset in an abutting arrangement of the saw arm. In the resetting there is only a positioning of the saw head and no processing of the workpiece. The time required for the positioning above all extends the nonproductive time given short cuts.
The object of the present invention is to develop a method for controlling a wall saw system with a high processing quality in which the nonproductive times for positioning the saw head and saw arm are reduced.
This object in the method for controlling a wall saw system is solved according to the invention by the features of the independent claim. Advantageous developments are indicated in the dependent claims.
The invention provides that the saw head in the controlled processing is moved such that after the pivoting movement of the saw arm to the new pivot angle a second limit of the wall saw facing the second end point coincides with the second end point, wherein the second limit of the wall saw is formed by a second upper exit point of the saw blade used facing the second end point on an upper side of the workpiece if the second end point is a free end point without barrier, by a second saw blade edge of the saw blade used facing the second end point, if the second end point is a barrier and the processing occurs without a blade guard, and by a second blade edge of the blade guard used facing the second end point if the second end point is a barrier and the processing occurs with a blade guard.
The inventive method for controlling a wall saw system has the advantage that a processing with an exclusively pulling saw arm is possible and nonproductive times for positioning the saw are reduced by a corresponding position control of the saw head. The second limit of the wall saw is used for controlling the method in the transition from the first main cut to the second main cut. The second limit is formed with a free end point without barrier by the second upper exit point of the saw blade used and with a barrier by the second saw blade edge (without blade guard) and the second blade guard edge (with blade guard).
Additionally preferred before the start of the processing controlled by the control unit is a length of the saw arm that is defined as the distance between the pivot axis of the saw arm and the axis of rotation of the saw blade, and that determines the distance between the pivot axis and the upper side of the workpiece. For a controlled processing of the separation cut, various parameters must be known to the control unit. These include the saw arm length, which represents a first device-specific size of the wall saw, and the vertical distance between the pivot axis and the surface of the workpiece, which besides the geometry of the wall saw also depends on the geometry of the guide rail used.
Additionally particularly preferred before the start of the controlled processing is a first width established for a blade guard used in the first main cut and a second width for a blade guard used in the second main cut, wherein the first and second widths are each comprised of a first distance of the pivot axis to the first blade guard edge and a second distance of the pivot axis to the second blade guard edge. If an end point represents a barrier, the position control of the saw head occurs through the blade guard edge facing the barrier of the blade guard used. With an asymmetrical blade guard, the first and second distances of the pivot axis to the blade guard edges are different, whereas with a symmetrical blade guard the first and second distances of the blade guard edges match the half-width of the blade guard.
The inventive control method is characterized in that the second limit of the wall saw after the pivoting movement of the saw arm to the new pivot angle coincides with the second end point. The new pivot angle in a first development corresponds to the first main cut angle of the first main cut and in a second development corresponds to the second main cut angle of the second main cut.
In the first development the saw arm is pivoted in the positive rotational direction from the negative first main cut angle into the positive first main cut angle and after the pivoting movement into the positive first main cut angle the second upper exit point of the saw blade used corresponds with the second end point if the pivot axis has a distance to the second end point of √[h1(D1−h1)]+δ sin(+α1), where h=h(+α1, D1)=D1/2−Δ−δ cos(+α1) designates the penetration depth of the saw blade used into the workpiece with the positive first main cut angle with the first diameter, the edge of the saw blade used corresponds with the second end point if the pivot axis has a distance to the second end point of D1/2+δ sin(+α1), and the second edge of the blade guard used coincides with the second end point if the pivot axis has a distance to the second end point of B1b+δ sin(+α1).
In the inventive method the saw arm is arranged exclusively pulling and the saw arm is pivoted in a position such that after the pivoting the second limit of the wall saw coincides with the second end point. Because of the pivot, residual material remains in the area of the pivot axis. The residual material of the first main cut in a first variant is completely removed in the first main cut and in a second variant is partly removed in the first main cut.
In the first variant the saw head is moved in a negative feed direction directed counter to the positive feed direction by a path length of at least 2δ|sin(+α1)| and the saw head is then positioned such that the second limit of the wall saw after the pivoting movement of the saw arm in the positive second main cut angle coincides with the second end point, wherein the second upper exit point coincides with the second end point if the pivot axis has a distance to the second end point of √[h2(D2−h2)]+δ sin(+α2), where h2=h(+α2, D2)=D2/2−Δ−δ cos(+α2) designates the penetration depth of the saw blade used into the workpiece with the positive second main cut angle with the second diameter, the second edge of the saw blade used corresponds with the second end point if the pivot axis has a distance to the second end point of D2/2+δ sin(+α2), and the second edge of the blade guard used coincides with the second end point if the pivot axis has a distance to the second end point of B2b+δ sin(+α2).
The first variant is identified as complete removal of the residual material. The path length is set such that the remaining material not removed by the pivoting of the saw arm is completely covered. After the removal of the residual material the saw head is positioned for the second main cut, wherein with a free end point without barrier the second upper exit point is used, with barrier the second saw blade edge with the second blade guard edge, depending on whether the processing occurs with or without blade guard. The first variant has the advantage that the residual material is fully removed in the first main cut and in the second main cut only the depth of cut of the second main cut must be removed. Consequently, the first variant is suitable for lower-power drive motors.
In the second variant the saw head is moved in the negative feed direction such that the second limit of the wall saw after the pivoting movement of the saw arm in the positive second main cut angle coincides with the second end point, wherein the second upper exit point of the saw blade used coincides with the second end point if the pivot axis has a distance to the second end point of √[h2(D2−h2)]+δ sin(+α2), where h2=h(+α2, D2)=D2/2−Δ−δ cos(+α2) designates the penetration depth of the saw blade used into the workpiece with the positive second main cut angle with the second diameter, the second edge of the saw blade used coincides with the second end point if the pivot axis has a distance to the second end point of D2/2+δ sin(+α2), and the second edge of the blade guard used coincides with the second end point if the pivot axis has a distance to the second end point of B2b+δ sin(+α2).
The second variant is identified as partial removal of the residual material. The removal of the residual material and the positioning of the saw head for the second main cut are combined. After the pivoting of the saw arm in the positive first main cut angle the saw head is moved until the pivot axis has a defined distance to the second end point E2. The distance depends on whether the end point represents a free end point without barrier or, if the end point has a barrier, the processing occurs with or without blade guard. The distance is set such that the second limit of the wall saw after the pivoting movement in the positive second main cut angle coincides with the second end point E2. The second variant has the advantage that the removal of the residual material and positioning for the second main cut are combined and the additional positioning step is eliminated; on the other hand, in the second main cut a greater depth of cut must be removed. Consequently, the second variant is suitable for powerful wall saws.
In the second development, the saw arm is rotated in the positive rotational direction from the negative first main cut angle into the positive second main cut angle and after the rotational movement into the positive second main cut angle the second upper exit point of the saw blade used coincides with the second end point if the pivot axis has a distance to the second end point, of √[h2(D2−h2)]+δ sin(+α2), where h2=h(+α2, D2)=D2/2−Δ−δ cos(+α2) designates the penetration depth of the saw blade used into the workpiece with the positive second main cut angle with the second diameter, the second edge of the saw blade used coincides with the second end point if the pivot axis has a distance to the second end point of D2/2+δ sin(+α2), and the second edge of the blade guard used coincides with the second end point if the pivot axis has a distance to the second end point of B2b+δ sin(+α2).
The second development of the control method dispenses completely with a removal of the residual, material in the first main cut. The distance is set such that the second limit of the wall saw after the pivoting movement of the saw arm into the positive second main cut angle coincides with the second end point. This variant without removal of the residual material has the lowest nonproductive times; however, a stronger drive motor for the saw blade is necessary that can process the greater depth of cut at the end point.
Particularly preferred is the saw head with the saw arm inclined under the positive second main cut angle moved in the negative feed direction. The saw head is then moved in the processing controlled by the control unit such that a first limit of the wall saw facing the first end point after the pivoting movement of the saw arm from the positive second main cut angle into a new pivot angle coincides with the first end point, wherein the first limit of the wall saw is formed by a first upper exit point facing the first end point of the saw blade used on the upper side of the workpiece if the first end point is a free end point without barrier, by a first edge facing the first end point of the saw blade used if the first end point is a barrier and the processing occurs without blade guard, and by the first blade guard edge facing the first end point of the blade guard used if the first end point is a barrier and the processing is done with a blade guard.
The inventive method is characterized in that the first limit of the wall saw facing the first end point is also used for the control. After the pivoting movement of the saw arm into the new pivot angle the first limit of the wall saw coincides with the first end point, the new pivot angle in a first development corresponds to the negative second main cut angle of the second main cut and in a second development corresponds to the negative third main cut angle of the subsequent third main cut.
In the first development, the saw arm is pivoted in the negative rotational direction from the positive second main cut angle into the negative second main cut angle and after the pivoting movement into the negative second main cut angle the first upper exit point of the saw blade used coincides with the first end point if the pivot axis has a distance to the first end point of √[h2(D2−h2)]+δ sin(+α2), where h2=h(−α2, D2)=D2/2−Δ−δ cos(−α2) designates the penetration depth of the saw blade used into the workpiece with the negative second main cut angle with the second diameter, the first edge of the saw blade used coincides with the first end point if the pivot axis has a distance to the first end point of D2/2−δ sin(−α2), and the first edge of the blade guard, used coincides with the first end point if the pivot axis has a distance to the first end point of B2a−δ sin(−α2).
In a first embodiment, the second main cut is the last main cut of the main cutting sequence. The saw arm is pivoted in the negative rotational direction from the positive second main cut angle into the negative second main cut angle and after the pivoting movement into the negative second main cut angle the first upper exit point of the saw blade used coincides with the first end point if the pivot axis has a distance to the first end point of √[h2(D2−h2)]−δ sin(−α2), where h2=h(+α2, D2)=D2/2−Δ−δ cos(−α2) designates the penetration depth of the saw blade used into the workpiece with the negative second main cut angle with the second diameter, the first edge of the saw blade used coincides with the first end point if the pivot axis has a distance to the first end point of D2/2−δ sin(−α2), and the first edge of the blade guard used coincides with the first end point if the pivot axis has a distance to the first end point of B2a−δ sin(−α2).
Preferably, the saw head in the positive feed direction with saw arm inclined at the negative second main cut angle is moved by a path length of at least 2δ|sin(−α2)|. This path length assures that the residual material of the second main cut is fully carried away.
Alternatively, the main cutting sequence comprises a third main cut performed after the second main cut with a third main cutting angle of the saw arm, a third diameter of the saw blade used and a third width of the blade guard used with a first and a second distance to the blade guard edges, wherein the saw arm in the third main cut is in a pulling arrangement and the saw head is moved in the positive feed direction.
In a first variant, the saw head is moved in the negative feed direction such that the first limit of the wall saw after the pivoting movement of the saw arm into the negative second main cut angle coincides with the first end point, wherein the first limit is formed by the first upper exit point facing the first end point of the saw blade used on the upper side of the workpiece if the first end point is a free end point without barrier, by a first edge facing the first end point of the saw blade used if the first end point is a barrier and the processing occurs without blade guard, and by a first edge facing the first end point of the blade guard used if the first end point is a barrier and the processing occurs with a blade guard.
To carry away the residual material, the saw head in the first feed direction with the saw arm inclined at the negative second main cutting angle is moved by a path length of at least 2δ|sin(−α2)| and the saw head is subsequently positioned such that the first limit of the wall saw after the pivoting movement of the saw arm in the negative third main cutting angle coincides with the first end point, wherein the first upper exit, point of the saw blade used coincides with the first end point if the pivot axis has a distance to the first end point (E1) of √[h3(D3−h3)]−δ sin(−α3), where h3=h(−α3, D3)=D3/2−Δ−δ cos(−α3) designates the penetration depth of the saw blade used into the workpiece with the negative third main cutting angle with the third diameter, the first edge of the saw blade used coincides with the first end point (E1) if the pivot, axis has a distance to the first end point of D3/2−δ sin(−α3), and the first edge of the blade guard used coincides with the first end point if the pivot axis has a distance to the first end point of B3a−δ sin(−α3).
In a second variant the saw head is moved in the positive feed direction such that the first limit of the wall saw after the pivoting movement of the saw arm into the negative third main cutting angle coincides with the first end point, wherein the first upper exit point of the saw blade used coincides with the first end point if the pivot axis has a distance to the first end point of √[h3(D3−h3)]−δ sin(−α3), where h3=h(1α3, D3)=D3/2−Δ−δ cos(−α3) designates the penetration depth of the saw blade used into the workpiece with the negative third main cutting angle with the third diameter, the first edge of the saw blade used coincides with the first end point if the pivot axis has a distance to the first end point of D3/2−δ sin(−α3), and the first edge of the blade guard used coincides with the first end point if the pivot axis has a distance to the first end point of B3a−δ sin(−α3).
In a third variant, the saw arm is pivoted in the negative rotational direction from the positive second main cutting angle into the negative third main cutting angle and after the pivoting movement into the negative third main cutting angle the first upper exit point of the saw blade used coincides with the first end point if the pivot axis has a distance to the first end point of √[h3(D3−h3)]+δ sin(−α3), where h3=h(−α3, D3)=D3/2−Δ−δ cos(−α3) designates the penetration depth of the saw blade used into the workpiece with the negative third main cutting angle (−α3) with the third diameter, the first edge of the saw blade used coincides with the first end point if the pivot axis has a distance to the first end point (E1) of D3/2−δ sin(−α3), and the first edge of the blade guard used coincides with the first end point if the pivot axis has a distance to the first end point of B3a−δ sin(−α3).
The third variant dispenses completely with a removal of the residual material in the second main cut. The distance is set such that the first limit of the wall saw after the pivoting movement of the saw arm coincides with the first end point. The variant without removal, of the residual material has the lowest nonproductive times; however, a stronger drive motor is necessary that can process the greater depth of cut at the end point.
The first and second main cuts are done with a saw blade and a blade guard, or alternatively the first main cut is done with a first saw blade and a first blade guard, wherein the first saw blade has a first saw blade diameter and the first blade guard has a first blade guard width and the second main cut is done with a second saw blade and a second blade guard wherein the second saw blade has a second saw blade diameter and the second blade guard has a second blade guard width.
In a preferred variant, the first main cut of the main cutting sequence is a precut and the saw head after the start of the processing controlled by the control unit is positioned in a start position, wherein in the start position the first limit of the wall saw facing the first end point after the pivoting movement into the negative first main cutting angle coincides with the first end point.
The first upper exit point of the saw blade used coincides with the first end point if the pivot axis has a distance to the first end point of √[h1(D1−h1)]−δ sin(−α1), where h1=h(α1, D1)=D1/2−Δ−δ cos(−α1) designates the penetration depth of the saw head used into the workpiece with the negative first main cutting angle with the first diameter, the first edge of the saw blade used coincides with the first end point if the pivot axis has a distance to the first end point of D1/2−δ sin(−α1), and the first edge of the blade guard used coincides with the first end point if the pivot axis has a distance to the first end point of B1a−δ sin(−α1).
The inventive method applies to all main cuts in which the main cutting angle is smaller than or equal to a critical pivot angle. The critical pivot angle corresponds to ±90° if the end point is a barrier, and the critical pivot angle corresponds to 180°—across[Δ/(δ+D/2] if the end point is a free end point without barrier.
Embodiments of the invention are described below based on the drawings. These do not necessarily represent the embodiments to scale; instead, where helpful for the explanation the drawings are produced in schematic and/or slightly distorted form. Regarding additions to the teachings directly evident from the drawings, reference is made to the relevant prior art. It must be kept in mind that various modifications and changes to the form and detail of an embodiment can be made without deviating from the general idea of the invention. The invention's features disclosed in the description, drawings and claims can be essential both individually and in any combination for the development of the invention. In addition, all combinations of at least two of the features described in the description, drawings and/or claims fall within the framework of the invention. The general idea of the invention is not restricted to the exact shape or detail of the embodiments shown and described below or restricted to a subject matter that would be restricted compared to the subject matter claimed in the claims. Where dimension areas are given, values lying inside the given boundaries are also disclosed as limit values and can be used and claimed randomly. For the sake of simplicity, the same reference signs are used below for identical or similar parts or parts with identical or similar function.